A Certain 177th Branch
by Tintin The King
Summary: (A.U.) Saten Riuko watched a few to many cop shows as a kid, or maybe just enough. Misaka Mikoto saw so much evil, but also those who fought against it. Now a certain branch, of a certain organization, is suited up to face the troubles of the city head on.
1. Chapter 1

**Author's Note**

 **Hello, welcome to my fanfic.**

 **This is my first foray into writing fanfiction but I assure you I am a** **veteran reader.**

 **This story is an A.U. which takes place in a universe where both Saten and Misaka, for different reasons, joined Judgment. The primary ships are femslash with a few exceptions (Who to ship Touma with is pretty up in the air) but I hope that doesn't dissuade you if you do ship something different, the romance between pairings will be slower anyway, as this isn't _meant_ to be a romance (Sometimes I have difficulty not writing romantic tension). I have not started watching the primary anime (A Certain Magical Index) or finished the spin-off (The one I'm writing about) but I do make sure to do research before I write. If their are questions or you do see something you think is entirely wrong, please leave a review. If you are interested in the progress of this story, maybe follow or favorite the fic. **

**I hope to have a chapter every 1 or 2 weeks.**

 **Authors notes will not be in every chapter, but if they are, they will be at the end of a chapter from now on.**

 **Anyway, hope you enjoy.**

* * *

Human cities are modeled like a human body. Networks of roadways and utility services act as vessels and nerves while governing bodies (despite what the citizen of said town might say) act as the brain. The best parallel is between law enforcement systems and immune systems. White blood cells and other immune cells act as protectors of the body. A good and healthy immune system keeps the body healthy, while a bad immune system can becomes worse than the illness they are made to protect against.

Saten Ruiko believed Academy City had a pretty good immune system. Considering it had someone akin to mythical cure-all within its ranks.

'She works fast.' Ruiko thought as she watched her senpai shock some thugs senseless. Of course, the famed "Judgement from Heaven" Misaka Mikoto was certainly not fond of entertaining any banter and preferred abating both her frustration and the injustices she saw as fast as possible. Ruiko poked one of the crispy criminals with her foot, receiving a pained groan in return.

"Anti-Skill should be over shortly, Misaka-sama." A kind voice over their headsets said. Uiharu Kazari was their goalkeeper, the person providing all intel between their squad.

"Copy that, Uiharu. Thank you."

A third voice, and person, appeared, spooking a stirred thug back to unconsciousness, "Onee-sama, you are too eager to do damage, as usual." The new voice was Shirai Kuroko, which, according to an amusing urban legend, was 'ruled body and soul by the greatest electromaster'. A statement she would probably agree with wholeheartedly.

"Personally, I think she might have held back. One of them woke up for a second there." Ruiko interjected, the corner of her mouth pushing up slightly. She knelt down with a pair of handcuffs, readying the troublemakers for pick-up.

"Did you catch the runner Kuroko?" Mikoto responded, starting to cuff the thugs closer to her.

"Yes, Onee-sama!", was the enthusiastic response.

"Good, Uiharu, can I get an ETA on Anti-Skill?"

"A van should pull up in forty-five seconds."

"What was our response time?"

A second passed as Kazari did some inspection. "The issue was resolved in 2 minutes and 57 seconds, lower than the national average by 2 minutes."

Mikoto nodded and smiled slightly.

"Not bad, we can see if we can get that lower later."

* * *

Bzzt! Thunk! Curchunck!

It amused Ruiko how casually her Sergeant broke some rules. Kuroko had of course facepalmed and attempted to make herself as not visible as possible as our honorable sergeant disregarded her position and zapped an innocent vending machine for a free drink.

"Onee-sama, why must you still wear those childish shorts underneath your school uniform."

Our esteemed Sergeant flushed red and coughed some of her soda out. "Perverted kouhai go to HR meetings for accosting their senpai. Long, boring meetings." She said as she simultaneously did something Ruiko thought HR may disagree with, in shocking her younger colleague, after doing something HR would certainly disagree with, stealing a soda from a bugged-out vending machine. A large shadow then passed over Ruiko.

"System scans today," Ruiko spoke up, drawing the attention of her friends. They looked to her, then followed her eyes to a blimp hanging in the sky. "I better be off."

"Yeah, see ya, Ruiko." Mikoto sounded distracted as she continued staring at the blimp.

"Let's meet after school at the usual place. See ya Ruiko-chan." She then grabbed Mikoto's hand and they were gone. Teleported away in a blink.

Ruiko felt some envy towards the convenience of such a power but quickly shook it off and headed in the opposite direction towards her own school.

As she started off, she opened up her comm link to Kazari.

"Morning, Uiharu-chan."

"Ah-h, Saten-san, is something wrong? Did you run into trouble on your way to school?" A worried tone, being the only detectable flavor to the voice. A rather overpowering flavor at that.

"No, no just figured we could talk and walk."

"We shouldn't use official channels for talking casually. If an emergency arises it must remain free." A chastising tone with undertones of exasperation and fondness.

A smile grew on Ruiko's face and breeze blew through her chest. A wonderful flavor for a voice.

"Fine, fine, I'll meet you at school then, in about 5 minutes." She hung up before Kazari could get another word in and put her comm in her bag, along with her Judgment sachet.

As she continued her walk, her thoughts went back to thoughts of the System Scan. The results were almost certain, making the test a waste of time. It would certainly say that she was a level 0, bottom of the totem pole. But even so, she held hope that maybe this time the test would pick something up missed by the dozens of tests previous. Of course, the scan also tested other aspects of your fitness, such as endurance, strength, and brain health. In this regard, she was at least happy with her progress. She was at least as fit as Kuroko, though not as skilled a fighter, even disregarding Kuroko's ability. Her grades may be average but Ruiko knew her talents were suited to less academic pursuits and so she didn't put much mind towards them. That was more Kazari's area anyway. And, of course, Mikoto's…

Her thoughts were interrupted by the sight of Kazari coming into sight and looking at her phone. A mischievous smile made its way onto Ruiko's face. Theories and ideas ran through her head as she approached her friend quietly from behind. She gently crouched and grabbed the bottom of the lovely skirt in front of her. Then with all her power, threw its bottom skyward, showing off Kazari's backside to all who could see.

"Ah, I suddenly feel nostalgic for the summer sun at a crowded beach, but these certainly create a similar effect, huh, Uiharu-chan."

The effect of her words was immediate. The shorter girl jumped away, did a 180 degree turn, gained a vibrant red hue, and began smacking Ruiko's front.

"Saten-san, why must you do this to me?" Her voice rose slightly at the end. Very cute.

"So formal with your friend and colleague Uiharu-chan," A bell went off. Too soon. "Lets walk in together." She turned Kazari towards the door and put her arms around the slightly shorter girls neck.

"Ruiko-san, you troublemaker." Her face still red and her petulant tone making her appear cuter. Ruiko laughed as they walked towards their scan. Renewed vigor within her she decide it had been a good morning despite the hold ups. Her friends were great.


	2. Chapter 2

_Cracka-thoom._

The cracking sound of her powers was comforting. The tests less so. She understood the importance of them, but testing always made her uneasy. Mikoto let another bolt of her lightning fly.

"Thank you, Misaka-san, that should be enough of that, now we would like to test your railgun at this distance."

Mikoto took out an arcade token, wordlessly, taking aim at a pool. Some tests done further away as it would allow her to test her accuracy at a distance. Waiting for confirmation, she slowed her breathing. Firing her railgun always calmed her, she had never felt anything but calm when she released it. All other emotions were released with the projectile.

"Fi-"

She fired as the word left the teacher's mouth. As she fired there was a need to push this one as hard as she could. The coin blasted forward at speeds far exceeding a bullet. Outstripped almost any man-made projectile or vehicle.

"-re!"

The water would not stay in the pool. It would soak the pavement and instructor. Mikoto could tell that with the excess power, her aim was off. Three centimeters to the right. It would hit the outer edge of the center circle. Her accuracy had gone up, which she allowed herself to feel proud about. Still not as accurate as it could be but if she continues to push herself she could get it to where it needed to be. The coin embedded itself in the target.

 _Bang._

From 700 meters away, any military grade sniper without having to worry about drop-off or air resistance would have perfect accuracy. She knew this. So while the result was certain to impress the instructor, she couldn't let herself be satisfied with where she was. The progress she allowed, but not her current position. She had to keep moving forward towards a new goal marker.

 _Baroom._

The instructor was about to fall off his feet. He hadn't braced himself. He had stood in the middle of the makeshift shooting range, offset by a couple of feet to the right of center. A nondescript, mousy teacher. She couldn't even remember if she had him as an instructor before. It didn't matter. The adults in the city could rarely trust to do anything right.

 _Thunk._

Water from the pool splashed from the pool in a drizzle across the cement as the instructor fell to the ground, getting soaked. Hopefully, they had enough data to finish. Despite wanting to know the results, she was sure she knew how to improve the railgun and saw little need to have instructors test it. Curious about the results of the rest of the test as she was, she could figure her railgun out better than they could anyway.

 _Splash._

"A-ah, quite impressive Misaka-san.", the mousy man said, rising and shaking himself of water, "Looks like we are finished then. As there isn't anywhere to fire anymore."

Mikoto had known that would happen when she had shot it. Without the water dampening, it was much too dangerous to shoot a railgun anywhere. Tests like this usually required slowly working up in power but she didn't want another half hour of unneeded tests. At least this way she could see how much she had improved since last year in power and accuracy.

"Grades will be ready soon Mikoto-san and as there is nothing more for you to do, you may join the other girls in the showers."

Mikoto nodded, walking past him, stretching her arms out above her.

* * *

 _Cracka-thoom._

Kuroko looked away from the rude person in front of her. Towards the area, she knew Onee-sama was doing her scan. Divided from everyone else for their safety. If Onee-sama were to let loose without the precautions, many of the other students would get hurt. Not that Onee-Sama would ever allow that to happen. No, she would first chastise the instructors for such stupidity and then force a proper training field. The instructors also had other reason to separate her.

She noted a charge in the air. Most wouldn't, but she knew that feeling better than anyone.

 _Bang-Baaroom-thunk-plash!_

The sound was accompanied by a shaking of the foundation of the school. Onee-sama had let loose. The girl she had been talking with- though it was more of a verbal spar- had fallen onto her backside. Kongou Mitsuko, a second-year transfer student.

"As a new transfer, you probably don't know. The student being tested over their is, in fact, the 'Ace of Tokiwadai'. If not for the dampening effect of that pool, the instructors would never be able to properly measure her abilities. So if you think you could take her on…" Kuroko's ears were still ringing.

"If you have done all your tests you may head to the showers, if you have missed something come talk to me." An instructor called out. Kuroko, took a second to listen. 'Sounds like Onee-sama is done.' A wicked smile appeared on her face.

* * *

"You dummy!" Kuroko simply leaned into her friend more.

"Oh, Onee-sama, I couldn't help myself." A lecherous grin made its way onto her face. "To see your body in all its nude glory! I am only human!"

The nearby tables were lit up with a camera-flash like brightness. Kuroko let out a groan and decided against good reason to slide into Mikoto's lap. Not something Mikoto would normally be angry about. But normally, one did not fall face first into her lap, nor does that person start to breath very deeply through their nose.

"Y-you pervert!" Mikoto turned bright red and stood quickly, resulting in Kuroko falling to the floor of the booth with a squeak. Kuroko felt she might have been turned into a roast chicken if her other friends hadn't walked into the restaurant at that moment.

"What's up?" Ruiko looked amused at the scene in front of her. Uiharu at least held her hand over mouth to hide her, still obvious, laughter.

"Ruiko-dono," Ruiko looked even more amused, "as you can see from my current state, Onee-sama has lost her mind. I mean, who wouldn't want their adorable kohai to fall in love with them. You and Uiharu-dono must help me to take her down. Once she's tied down, I know exactly how to bring her back to us."

Mikoto turned even redder and started to sputter. At this Uiharu couldn't hold her laughter and let out a giggle, and Ruiko also let out a laugh.

As the group wound down a bit and took their seats, Mikoto taking a seat opposite Kuroko, Uiharu asked them about the System scan.

Kuroko let her head fall back as she looked to the roof of the establishment.

"Twenty kilograms and fifteen meters up from last year. So I can move 140 kilograms to about ninety meters away. Probably from having to lug the three of you around." She gestured generally around the table, then shrugged, "Otherwise, everything was as expected."

"Great Improvement, Kuroko." Mikoto's voice made her blush. Genuine compliments from Onee-sama always did.

"I improved as well but not by any notable metrics." Kuroko held back a sigh. Her Onee-sama held herself to a high standard. "How about you guys?"

"Still a zero on my end, sadly." Ruiko shook her head. "Grades were fine, fitness was better, overall what I expected. Uiharu-chan has some better news."

All three other girls looked at Uiharu, two expectantly, one proudly.

Uiharu dug around in her bag for a second before pulling out a card. She showed the front of it to her friends. The grades on it were ignored in favour of something much more interesting.

"Level 2! Congratulations!" Kuroko leant across the table and hugged her.

"Great Job, Uiharu-chan!" Onee-sama stood up suddenly. "As celebration we should get something special today."

"A crepe stand near by was doing a special today, for those frog toys?" Ruiko put on a thinking expression.

Mikoto's eyes lit up. "I'll buy."

* * *

Uiharu took another bite from her crepe. She had opted for a sweet one over savory. Misaka-sama was ignoring her crepe in favour of looking lovingly at the frog toy she had received from the vendor. They had received three -the last three- but Ruiko-san had forgone one. She had said it didn't fit her style as well. Uiharu knew she was making sure that Misaka would take one herself.

The sound of shattering glass as well as the ring of an alarm. In practiced movements they put on their armbands and inserted ear pieces.

Uiharu took out her laptop looking at the security cameras in the area. "Three assailants, 30 seconds to full ID. Only mild injuries inside, but the building has been damaged. One or more are strong espers, probably a pyrokinetic. Contacting Anti-Skill now, Misaka-sama."

"Roger that."

"Perimeter set, all civilians are safe thirty feet back, buses between them and the robbers." Ruiko's voice paused, "Bad news though, a teacher says one of her students wandered off, he is unaccounted for, Misaka-san."

"Roger that, everyone priority one is to keep that kid safe, lets deal with this quickly, over."

Uiharu looked up to look at Misaka's face. A slight frown had formed. Uiharu looked back at her screen.

"Five minutes to Anti-Skill, Misaka-sama."

"I'll continue to look for the kid, Misaka-san."

"I'm ready to engage, Onee-sama."

"Uiharu, report."

"One level one, pyrokinetic. And two zeros, Misaka-sama."

"You may engage Kuroko, over."

Uiharu switched her camera to one watching the street to watch the conflict. Kuroko calmly asked them to surrender. The robbers tense up but one steps forward. He says something Uiharu is unable to hear and a fireball appears in his hand. Then Kuroko teleports to one of the guys behind him, kicks that guy in the head, dealing with one of the threats. The other guy scrambles away while the pyro throws the fireball at Kuroko. It doesn't come close to hitting her. The pyro then ducks a kick from Kuroko, but is unable to dodge the force of the subsequent jab to the stomach. Kuroko had teleported as soon as she had missed and brought the force of the previous kick into the new hit now aimed for the guys stomach. A swift hit to the head knocks the pyro unconscious. She turns to the last guy but he's now holding the shirt of the child they had been looking for.

"Don't come any closer!" The guy pulls the child along, towards one of the cars parked along the road. Uiharu looks to Misaka. She frowns deeper but then she smiles. Uiharu's confused but when she looks down at the screen again she understands.

"I'm coming in, over." Misaka walks between the busses.

Uiharu watches through the screen as Ruiko leaps from between the last two cars and grabs the boy from the robber. He tries to grab them back but Ruiko is already out before he can do more.

He cusses, throwing the stolen goods into the passenger seat. He starts the vehicle and backs it onto the street. The robber looks up and sees Misaka in the middle of the street. He jams his foot down on the gas pedal.

Misaka watches as the vehicle approaches her a rapidly increasing speed. Some onlookers look away, not able to stomach the inevitable crash. Kuroko starts to cuff the two robbers who are unconscious around her. Uiharu keeps the camera feed open but starts to prepare the after action report. Ruiko checks the child over for injuries. All three look back when the car arrives at Mikoto. Her hand is raised, palm towards the vehicle.

At about one meter away, the vehicle rapidly comes to a stop, jarring the crook roughly into the steering wheel, an airbag popping out in the process. The guy is knocked unconscious by the force. Mikoto lowers her hand and takes some cuffs out of her bag. She strolls over to the driver side of the vehicle, pulls open the door, and pulls the unconscious robber out. Uiharu noted she was gentle with the unconscious man. Had he still been awake, she probably would have been a bit rougher.

She heard the blare of Anti-Skill sirens approach and prepared to meet the officer who would take their would-be-robbers to a holding cell for interrogation.

"Hey, Uiharu, do you copy?"

"Yes, Saten-san, I copy."

"Can you tell the Anti-Skill guy to tell us when the pyro wakes up? I've got some questions."

"Of course. What kind of questions?"

"Just a hunch, don't worry too much, Uiharu-chan. Thanks, over and out." Uiharu nodded absently. She was curious what Ruiko found interesting enough about a run-of-the-mill robbery, but was certain she would say if it was important. Decided on asking more later, she got back to work on the after action report.

* * *

 **Two weeks till the next one. 2000 words feels better to publish than 1000. Next chapter will be out on the 21st. Also probably some one-shots for both action and romance between releases. Hope you enjoy the chapter, please favorite and follow. Leave a review if you have any questions or concerns (or if you really loved or hated it. Have a good two weeks.**


End file.
